interop between browser js and commonjs

browser.html

<script type="text/javascript" src="namespace.js"></script>
<script type="text/javascript" src="example.module.js"></script>
<script type="text/javascript">
    console.log(example.module.test_fn("hello", "world"));
</script>

common.js

var module = require('./example.module'),
    sys = require('sys');

sys.puts(module.test_fn('hello', 'world'));

example.module.js

var get_global_object, exp=null;
try {
    exp = exports;
    get_global_object = require('./namespace').get_global_object;
} catch(Error) {}

(function(global) {
    var exporter = global.getExporter('module');
    var test_fn = function() {
        return arguments;
    };

    exporter('test_fn', test_fn);
})(get_global_object('example', exp);

namespace.js

function documentNamespace(namespace) {
    return {
        'require':function(what) {
            var split = what.split('.'),
                retval = window;
            for(var i = 0, len = split.length; i < len; ++i) {
                retval = retval[split[i]];
            }
            return retval;
        },
        'getExporter':function(name) {
            window[namespace][name] = (window[namespace][name] === undefined) ? {} : window[namespace][name];
            return function(export_name, to_export) {
                window[namespace][name][export_name] = to_export;
            };
        },
    }
}

function commonjsNamespace(exp) {
    exp['require'] = function(what) {
        return require(['./',what].join(''));
    };
    exp['getExporter'] = function(name) {
        var self = this;
        return function(export_name, to_export) {
            self[export_name] = to_export;
        };
    };
    return exp;
}

function get_global_object(namespace, exp) {
    if(exp) {
        return commonjsNamespace(exp);
    }

    if(window[namespace]) {
        return window[namespace];
    } else {
        window[namespace] = documentNamespace(namespace);
        return window[namespace];
    }
}
try {
    exports.get_global_object = get_global_object;
} catch(Error) {}